An adder can add an arbitrary number of bits, along with a carry into the low order bit position, and generate the sum and a carry from the high order bit.
The propagation delay of the adder is proportional to the number of bits added. It essentially simulates a simple ripple carry adder.
Set the number of bits being added by entering a number or using the keypad. Click on OK to place the element, or Cancel to cancel its creation.